{"@ID": "663", "@Name": "Use of a Non-reentrant Function in a Concurrent Context", "@Abstraction": "Base", "@Structure": "Simple", "@Status": "Draft", "Description": "The product calls a non-reentrant function in a concurrent context in which a competing code sequence (e.g. thread or signal handler) may have an opportunity to call the same function or otherwise influence its state.", "Related_Weaknesses": {"Related_Weakness": {"@Nature": "ChildOf", "@CWE_ID": "662", "@View_ID": "1000", "@Ordinal": "Primary"}}, "Weakness_Ordinalities": {"Weakness_Ordinality": {"Ordinality": "Primary"}}, "Applicable_Platforms": {"Language": [{"@Class": "Not Language-Specific", "@Prevalence": "Undetermined"}, {"@Name": "C", "@Prevalence": "Undetermined"}]}, "Modes_Of_Introduction": {"Introduction": {"Phase": "Implementation"}}, "Common_Consequences": {"Consequence": {"Scope": ["Integrity", "Confidentiality", "Other"], "Impact": ["Modify Memory", "Read Memory", "Modify Application Data", "Read Application Data", "Alter Execution Logic"]}}, "Detection_Methods": {"Detection_Method": {"@Detection_Method_ID": "DM-14", "Method": "Automated Static Analysis", "Description": "Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect \"sources\" (origins of input) with \"sinks\" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)", "Effectiveness": "High"}}, "Potential_Mitigations": {"Mitigation": [{"Phase": "Implementation", "Description": "Use reentrant functions if available."}, {"Phase": "Implementation", "Description": "Add synchronization to your non-reentrant function."}, {"Phase": "Implementation", "Description": "In Java, use the ReentrantLock Class."}]}, "Demonstrative_Examples": {"Demonstrative_Example": [{"@Demonstrative_Example_ID": "DX-171", "Intro_Text": "In this example, a signal handler uses syslog() to log a message:", "Example_Code": {"@Nature": "Bad", "@Language": "C", "xhtml:div": {"xhtml:br": [null, null], "xhtml:div": [{"@style": "margin-left:1em;", "xhtml:br": [null, null], "#text": "syslog(LOG_NOTICE,\"%s\\n\",message);sleep(10);exit(0);"}, {"@style": "margin-left:1em;", "xhtml:br": [null, null, null, null], "#text": "...signal(SIGHUP,sh);signal(SIGTERM,sh);sleep(10);exit(0);"}, "If the execution of the first call to the signal handler is suspended after invoking syslog(), and the signal handler is called a second time, the memory allocated by syslog() enters an undefined, and possibly, exploitable state."], "#text": "char *message;void sh(int dummy) {}int main(int argc,char* argv[]) {}"}}}, {"@Demonstrative_Example_ID": "DX-172", "Intro_Text": "The following code relies on getlogin() to determine whether or not a user is trusted. It is easily subverted.", "Example_Code": {"@Nature": "Bad", "@Language": "C", "xhtml:div": {"xhtml:br": null, "xhtml:div": [{"@style": "margin-left:1em;", "#text": "allow();"}, {"@style": "margin-left:1em;", "#text": "deny();"}], "#text": "pwd = getpwnam(getlogin());if (isTrustedGroup(pwd->pw_gid)) {} else {}"}}}]}, "Observed_Examples": {"Observed_Example": [{"Reference": "CVE-2001-1349", "Description": "unsafe calls to library functions from signal handler", "Link": "https://www.cve.org/CVERecord?id=CVE-2001-1349"}, {"Reference": "CVE-2004-2259", "Description": "SIGCHLD signal to FTP server can cause crash under heavy load while executing non-reentrant functions like malloc/free.", "Link": "https://www.cve.org/CVERecord?id=CVE-2004-2259"}]}, "Related_Attack_Patterns": {"Related_Attack_Pattern": {"@CAPEC_ID": "29"}}, "References": {"Reference": [{"@External_Reference_ID": "REF-547", "@Section": "Class ReentrantLock"}, {"@External_Reference_ID": "REF-548"}]}, "Mapping_Notes": {"Usage": "Allowed", "Rationale": "This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.", "Comments": "Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.", "Reasons": {"Reason": {"@Type": "Acceptable-Use"}}}, "Content_History": {"Submission": {"Submission_Name": "CWE Community", "Submission_Date": "2008-04-11", "Submission_Version": "Draft 9", "Submission_ReleaseDate": "2008-04-11", "Submission_Comment": "Submitted by members of the CWE community to extend early CWE versions"}, "Modification": [{"Modification_Name": "Eric Dalci", "Modification_Organization": "Cigital", "Modification_Date": "2008-07-01", "Modification_Version": "1.0", "Modification_ReleaseDate": "2008-09-09", "Modification_Comment": "updated References, Potential_Mitigations, Time_of_Introduction"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2008-09-08", "Modification_Version": "1.0", "Modification_ReleaseDate": "2008-09-09", "Modification_Comment": "updated Relationships, References"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2009-03-10", "Modification_Version": "1.3", "Modification_ReleaseDate": "2009-03-10", "Modification_Comment": "updated Related_Attack_Patterns"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2010-09-27", "Modification_Version": "1.10", "Modification_ReleaseDate": "2010-09-27", "Modification_Comment": "updated Name, Observed_Examples, Potential_Mitigations, References, Relationships"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2010-12-13", "Modification_Version": "1.11", "Modification_ReleaseDate": "2010-12-13", "Modification_Comment": "updated Description, Name, Relationships"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2011-06-01", "Modification_Version": "1.13", "Modification_ReleaseDate": "2011-06-01", "Modification_Comment": "updated Common_Consequences"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2012-05-11", "Modification_Version": "2.2", "Modification_ReleaseDate": "2012-05-15", "Modification_Comment": "updated Relationships"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2014-07-30", "Modification_Version": "2.8", "Modification_ReleaseDate": "2014-07-31", "Modification_Comment": "updated Relationships"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2017-11-08", "Modification_Version": "3.0", "Modification_ReleaseDate": "2017-11-08", "Modification_Comment": "updated Observed_Examples"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2020-02-24", "Modification_Version": "4.0", "Modification_ReleaseDate": "2020-02-24", "Modification_Comment": "updated Relationships"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2020-06-25", "Modification_Version": "4.1", "Modification_ReleaseDate": "2020-06-25", "Modification_Comment": "updated Relationships"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2020-12-10", "Modification_Version": "4.3", "Modification_ReleaseDate": "2020-12-10", "Modification_Comment": "updated Common_Consequences"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2023-01-31", "Modification_Version": "4.10", "Modification_ReleaseDate": "2023-01-31", "Modification_Comment": "updated Description"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2023-04-27", "Modification_Version": "4.11", "Modification_ReleaseDate": "2023-04-27", "Modification_Comment": "updated References, Relationships, Time_of_Introduction"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2023-06-29", "Modification_Version": "4.12", "Modification_ReleaseDate": "2023-06-29", "Modification_Comment": "updated Mapping_Notes"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2023-10-26", "Modification_Version": "4.13", "Modification_ReleaseDate": "2023-10-26", "Modification_Comment": "updated Demonstrative_Examples"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2025-04-03", "Modification_Version": "4.17", "Modification_ReleaseDate": "2025-04-03", "Modification_Comment": "updated Demonstrative_Examples"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2025-12-11", "Modification_Version": "4.19", "Modification_ReleaseDate": "2025-12-11", "Modification_Comment": "updated Applicable_Platforms, Detection_Factors, Weakness_Ordinalities"}], "Previous_Entry_Name": [{"@Date": "2010-09-27", "#text": "Use of a Non-reentrant Function in an Unsynchronized Context"}, {"@Date": "2010-12-13", "#text": "Use of a Non-reentrant Function in a Multithreaded Context"}]}}